Change in Cortical Vessel Signs on Susceptibility-Weighted Images after Full Recanalization in Hyperacute Ischemic Stroke

Abstract

Background: The cortical vessel signs (CVSs) on susceptibility-weighted images (SWIs) have been reported in patients with hyperacute ischemic stroke. We evaluated the change of this susceptibility sign on the immediate SWI after full recanalization and its clinical implications. Methods: Nineteen hyperacute ischemic stroke patients who had acute large artery occlusion and underwent post-recanalization SWI were enrolled in this study. The patients had ICA (internal carotid artery, 2 cases), M1 (M1 segment of middle cerebral artery, 7 cases), M2 (M2 segment of middle cerebral artery, 1 cases), T (intracranial ICA bifurcation, 2 cases), ICA/M1 (4 cases) and basilar artery (3 cases) occlusion on imaging studies before thrombolysis and they underwent immediate magnetic resonance imaging, including the SWI, after full recanalization. The recanalization status was evaluated using the thrombolysis in cerebral infarction (TICI) scorebefore and after thrombolysis. The SWI images were evaluated for the presence of asymmetry of veins over the ischemic territory and this was correlated with the site of stenosis or occlusion. The veins in the ischemic territory were classified as ‘prominent’ if there were more numerous veins and/or large veins with a greater signal loss observed compared with the opposite normal hemisphere, ‘equal’ if there were no significant difference in appearance in both the cerebral hemispheres, and ‘less’ if the veins were decreased in the affected area as compared with that of the normal cortex. Baseline clinical parameters and clinical outcomes were reviewed. Results: The initial TICI grades were 0 in all cases. After thrombolysis, TICI grades were 3 in all cases. The pre-recanalization SWIs were obtained in 10 of 19 patients and all 10 showed prominent CVSs over the affected side, which disappeared on the post-recanalization SWI. On the post-recanalization SWI, the observed veins in the affected area were equal (10/19), less (5/19), and both equal and less (4/19). Patients with equal cortical veins in the affected area had small lesions on diffusion-weighted image (DWI) (10/19), while patients with less cortical veins had medium to large lesions on DWI (9/19). Conclusion: The prominent CVSson SWI can be indicative of acute thromboembolic occlusion and its change immediately after recanalization can be used to reflect the metabolic status. After recanalization, the appearance of the equal CVS (return to normal) on SWI was associated with a favorable clinical outcome and infarction was avoided in our small series study.

Ipsilateral Prominent Thalamostriate Vein on Susceptibility-Weighted Imaging Predicts Poor Outcome after Intravenous Thrombolysis in Acute Ischemic Stroke

“…[1][2][3] Susceptibility-weighted imaging is useful for evaluating cerebral veins in AIS because it is extremely sensitive to paramagnetic substances such as deoxyhemoglobin, thus reflecting the oxygen extraction fraction and the cerebral metabolic rate of oxygen of the hypoxic tissue. [1][2][3][4] Shortly after vascular occlusion, the uncoupling between oxygen supply and demand in the hypoperfused region leads to an elevated oxygen extraction fraction and subsequent increased level of deoxyhemoglobin in the vessel, which contributes to prominent hypointensity of the draining veins on SWI. [5][6][7] Asymmetric cortical veins, which can be visualized on SWI after AIS and are considered an indicator of salvageable ischemic penumbra, were found to be associated with 3-month outcome.…”

“…On the basis of SWI, it was demonstrated that prominent hypointense cortical veins and medullary veins predicted infarct growth and poor outcome after AIS. 2 However, most of the included patients did not undergo revascularization therapy, and salvage of potentially penumbral regions was therefore unlikely. The imaging was also acquired up to 72 hours after AIS, which limits its applicability to hyperacute treatment decision-making.…”

Magnetic resonance susceptibility weighted imaging in neurosurgery: current applications and future perspectives

“…7,59 SWI can effectively determine the CVS to detect arterial occlusion 49 and the change in CVS preand postadministration of the thrombolytic agent to assess reperfusion levels. 7 Although CVS measurements offer precise information on the thrombotic region, a simpler detection method involves the presence of dilated and hypointense cortical vessels on SW images.…”

“…7,59 SWI can effectively determine the CVS to detect arterial occlusion 49 and the change in CVS preand postadministration of the thrombolytic agent to assess reperfusion levels. 7 Although CVS measurements offer precise information on the thrombotic region, a simpler detection method involves the presence of dilated and hypointense cortical vessels on SW images. 97 The dilated region on SWI correlates with MR angiography (MRA) findings 93 and could be used to monitor occlusion, 57 along with the possibility for hemorrhagic transformation, 57,64 over time.…”

“…A limited collection of studies has examined the ability of SWI to monitor outcome in stroke patients; 6,7,49,56,64 however, the method of monitoring stroke outcome has varied greatly between studies. Bai et al 6 have suggested that a greater amount of CMBs on SWI after reperfusion is predictive of a better outcome.…”